In Catechesis in the Later Middle Ages I: The Exposition of the Lord's Prayer of Jordan of Quedlinburg, OESA (d. 1380)--Introduction, Text, and Translation, E.L. Saak presents the first edition and translation of the Exposition of the Lord's Prayer by the fourteenth-century Augustinian hermit, Jordan of Quedlinburg. This work, the first of six planned volumes of Jordan's Opera Selecta, contributes to our understanding of late medieval catechesis by focusing on a major pillar thereof, namely, the Pater Noster, bringing to light the importance of the Lord's Prayer to late medieval religion and the impact of Jordan's text on later authors, contributing thereby as well to the understanding of the emergence of the Catechism in the Reformation.